Thermal Performance of Navy Anti-Exposure Coverall to Different Water ExposureConditions

摘要

The Navy's standard and a modified anti-exposure coverall were evaluated todetermine their thermal performance in calm and agitated water. The principle difference between the coveralls were the closures. The standard coverall was designed as a work garment which provides both buoyancy and thermal protection to cold water exposures in accidental and emergency immersions. In calm water the Effective Thermal Insulation Resistance (ETIR) value of the standard coverall was 19% higher than the modified coverall. In agitated water there was a major reduction in ETIR values for both coveralls compared to calm water because of substantial water entry into the head and neck areas of the coveralls. The overall reductions in ETIR values were 84-89% over the coverall area and 78-87% below the neck region for the standard and modified coveralls, respectively. The use of a cord tie-off in the neck region of the coveralls lowered the reduction in ETIR values below the neck region by 21-29% for the standard and modified coveralls respectively. The use of the cord tie-off increased survival times in agitated water from the 85 and 70 minutes estimated without it, to 140 and 120 minutes for the standard and modified coveralls, respectively.